Glued laminated wood and method of manufacturing the same

Abstract

Glued laminated wood which has a novel laminated structure and may be fabricated from small-sized veneer sheets, and method of manufacturing such laminated wood are provided. The glued laminated wood in its continuous form is made from a series of unit-length veneer sheets each having the same length and thickness which are laminated in a laid-up arrangement in which each of the veneer sheets is lapped on another and offset therefrom in the direction of its length at a regular interval determined by the number of plies to be in the laminated wood product and the length of the unit veneer sheets. It has a novel structure in that each veneer sheet therein has tandemly spaced straight length portions which are parallel to each other, but successively displaced from each other in the direction of the thickness of the product, there being a somewhat S-shaped curved length portion of the veneer sheet between any successive pair of these straight length portions. The number of such straight length portions in each unit veneer sheet is equal to the number of plies in the product being made, and the length of each such straight length portion is nominally determined by dividing the length of the unit veneer sheet by the number of plies.

What is claimed is: 
     
       1. Method of manufacturing glued laminated wood comprising providing a plurality of unit veneer sheets, applying glue to said unit veneer sheets, laying up said unit veneer sheets in successively lapped relation in one direction of overlap, each of said unit veneer sheets having substantially the same length in the direction of said laying-up, the successive length intervals of overlap of each said unit veneer sheet on another in said direction of overlap each being nominally equal to said unit veneer sheet length minus the quotient determined by dividing said unit veneer sheet length by the number of plies to be in said glued laminated wood, and pressing and curing said laid-up veneer sheets to permanently deform and bond the same and thereby establish the thickness of said glued laminated wood, each of said deformed unit veneer sheets having a plurality of straight length portions and respective curved length portions between any two adjacent ones of its said straight length portions, said straight length portions being in tandem parallel relation to each other and successively displaced from each other in the direction of the thickness of said glued laminated wood by a distance substantially equal to the thickness of the immediately adjacent, lapped veneer sheet. 
     
     
       2. Method according to claim 1, wherein each of said unit veneer sheets has equal thickness, and said length interval of overlap of each said unit veneer sheet on another is varied from said nominal length interval by a length which is up to 50 times the thickness of one of said unit veneer sheets. 
     
     
       3. Method according to claim 1, wherein said step of applying glue to said unit veneer sheets comprises arranging said unit veneer sheets in successively lapped relation in the direction of their said lengths, the length interval of overlap of each said unit veneer sheet on another in said arranging being nominally equal to said unit veneer sheet length divided by the number of plies to be in said glued laminated wood, coating said glue substantially continuously along those overlapped surfaces of said unit veneer sheets which face in one direction whereby said length interval on each unit veneer sheet is shielded from said coating of glue, and said subsequent step of laying up said unit veneer sheets comprises substantially reversing the length interval of overlap of said unit veneer sheets whereby said glue coating glues the respective of said sheets one to another in successively overlapped relation with said shielded length intervals on said sheets being exposed. 
     
     
       4. Method according to claim 3, wherein during said arranging of said unit veneer sheets, said overlapped unit veneer sheets are conveyed in said arrangement by a first conveying means with said glue-coated surfaces thereof facing upwardly, and said substantially reversing the length interval of overlap of said unit veneer sheets comprises feeding said unit veneer sheets one at a time off from said arrangement of said unit veneer sheets and laying up said unit veneer sheets while conveying the same by a second conveying means. 
     
     
       5. Method according to claim 4, wherein said step of substantially reversing the length interval of overlap comprises feeding said unit veneer sheets one at a time off from the underside of said arrangement of unit veneer sheets and dropping said unit veneer sheets on to said second conveying means, said second conveying means being disposed below said first conveying means, and conveying said sheets in direction which is substantially opposite to that of said first conveying means. 
     
     
       6. Method according to claim 2, wherein said length interval of overlap of each said unit veneer sheet on another is varied from said nominal length interval by a length which is up to 5 times the thickness of one of said unit veneer sheets. 
     
     
       7. Method according to claim 1, wherein each said unit veneer sheet comprises a solid sheet of veneer. 
     
     
       8. Method according to claim 1, wherein each said unit veneer sheet comprises at least two undersized sheets of veneer which are integrally jointed together to form said length of each said unit veneer sheet. 
     
     
       9. Method according to claim 8, wherein each said undersized sheet of veneer which is disposed at and forms an end of said unit veneer sheet has a length, as measured in the direction of said laying-up, which is greater than a dimension determined by dividing said unit veneer sheet length by the number of plies to be in said glued laminated wood. 
     
     
       10. Method according to claim 8, wherein each said undersized veneer sheet which is disposed at and forms an end of said unit veneer sheet has a length, as measured in the direction of said laying-up, which is greater than said dimension by an amount which is from about 5 to about 150 times the thickness of said unit veneer sheet.